Commit 1764c3ed authored by Sami Tolvanen's avatar Sami Tolvanen Committed by Catalin Marinas
Browse files

arm64: use a common .arch preamble for inline assembly 



Commit 7c78f67e ("arm64: enable tlbi range instructions") breaks
LLVM's integrated assembler, because -Wa,-march is only passed to
external assemblers and therefore, the new instructions are not enabled
when IAS is used.

This change adds a common architecture version preamble, which can be
used in inline assembly blocks that contain instructions that require
a newer architecture version, and uses it to fix __TLBI_0 and __TLBI_1
with ARM64_TLB_RANGE.

Fixes: 7c78f67e ("arm64: enable tlbi range instructions")
Signed-off-by: default avatarSami Tolvanen <samitolvanen@google.com>
Tested-by: default avatarNathan Chancellor <natechancellor@gmail.com>
Reviewed-by: default avatarNathan Chancellor <natechancellor@gmail.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/1106
Link: https://lore.kernel.org/r/20200827203608.1225689-1-samitolvanen@google.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent d012a719

arch/arm64/Makefile

+8 −3
Original line number Diff line number Diff line
@@ -82,8 +82,8 @@ endif 
# compiler to generate them and consequently to break the single image contract

# we pass it only to the assembler. This option is utilized only in case of non

# integrated assemblers.

ifneq ($(CONFIG_AS_HAS_ARMV8_4), y)

branch-prot-flags-$(CONFIG_AS_HAS_PAC) += -Wa,-march=armv8.3-a

ifeq ($(CONFIG_AS_HAS_PAC), y)

asm-arch := armv8.3-a

endif

endif
@@ -91,7 +91,12 @@ KBUILD_CFLAGS += $(branch-prot-flags-y) 


ifeq ($(CONFIG_AS_HAS_ARMV8_4), y)

# make sure to pass the newest target architecture to -march.

KBUILD_CFLAGS	+= -Wa,-march=armv8.4-a

asm-arch := armv8.4-a

endif



ifdef asm-arch

KBUILD_CFLAGS	+= -Wa,-march=$(asm-arch) \

		   -DARM64_ASM_ARCH='"$(asm-arch)"'

endif



ifeq ($(CONFIG_SHADOW_CALL_STACK), y)

arch/arm64/include/asm/compiler.h

+6 −0
Original line number Diff line number Diff line
@@ -2,6 +2,12 @@ 
#ifndef __ASM_COMPILER_H

#define __ASM_COMPILER_H



#ifdef ARM64_ASM_ARCH

#define ARM64_ASM_PREAMBLE ".arch " ARM64_ASM_ARCH "\n"

#else

#define ARM64_ASM_PREAMBLE

#endif



/*

 * The EL0/EL1 pointer bits used by a pointer authentication code.

 * This is dependent on TBI0/TBI1 being enabled, or bits 63:56 would also apply.

arch/arm64/include/asm/tlbflush.h

+4 −2
Original line number Diff line number Diff line
@@ -28,14 +28,16 @@ 
 * not. The macros handles invoking the asm with or without the

 * register argument as appropriate.

 */

#define __TLBI_0(op, arg) asm ("tlbi " #op "\n"				       \

#define __TLBI_0(op, arg) asm (ARM64_ASM_PREAMBLE			       \

			       "tlbi " #op "\n"				       \

		   ALTERNATIVE("nop\n			nop",		       \

			       "dsb ish\n		tlbi " #op,	       \

			       ARM64_WORKAROUND_REPEAT_TLBI,		       \

			       CONFIG_ARM64_WORKAROUND_REPEAT_TLBI)	       \

			    : : )



#define __TLBI_1(op, arg) asm ("tlbi " #op ", %0\n"			       \

#define __TLBI_1(op, arg) asm (ARM64_ASM_PREAMBLE			       \

			       "tlbi " #op ", %0\n"			       \

		   ALTERNATIVE("nop\n			nop",		       \

			       "dsb ish\n		tlbi " #op ", %0",     \

			       ARM64_WORKAROUND_REPEAT_TLBI,		       \

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